Grain elevator alarm switch



Nov. 30, 1937. L. P. DENDEL GRAIN ELEVATOR ALARM SWITCH Filed Sept. 19, 1933 2 Sheets-Sheet l ATTORNEY Nov. 30, 1937. L, P, DENDEL 2,100,710

GRAIN ELEVATOR ALARM SWITCH Filed Sept. 19, 1933 2 Sheets-Sheet 2 INVENTOR BY /MW/A%Qv@ ATTORN EY Patented Nov. 30, 1937 UNITED STATES i ATEhlT GFFICE 1 Claim.

This invention relates to grain elevator alarms, but it may be applied usefully to a variety of controllable contrivances.

An object of this invention is to provide an 5 alarm for use in association with the conveyor belts of grain elevators in order that due audible or visible alarm may be given the attendants whenever from any cause the conveyor belt is slowed up so that attention may be immediately given the apparatus.

This invention comprises a specially arranged and operated conveyor belt contact wheel, and speed responsive devices of special construction and arrangement operated thereby, those devices being adapted to actuate an electric switch, of particular form and construction when the travel of the belt is interrupted and whereby an alarm or other sufiicient signal may be given near by or at any distance.

In the accompanying drawings the particular and what is believed to be novel construction and arrangement of the difierent combined elements of this invention are illustrated.

Fig. 1 represents a side View of the upper part of a grain conveyor housing and conveyor, showing this invention applied thereto.

Fig. 2 is a vertical longitudinal view of the separable casing for the speed responsive devices, and exhibiting those devices in the casing.

Fig. 3 is a vertical cross section of tie parts set forth in Fig. 2 taken on the broken line 33 of Fig. 2, these views being on an enlarged scale as compared with Fig. 1.

Throughout the drawings and description the same number is used to refer to the same part.

Consider the drawings, the housing 1 supports the conveyor belt 2 with th customary buckets 3, and the belt passes over a sheave 4 as indicated in Fig. 1.

As best illustrated in Fig. 2 the casing of the speed responsive devices comprises two separable parts 5 and B. Part 6 is pivoted to the housing I, and part 5 is removably projecting therefrom. Part 5 may be taken off to get at the enclosed devices. Casing part 5 has a bearing extension 1 for the axis 8 or" the belt contact wheel 9. Axis 8 has a longitudinal hollow portion 10, with opposite slots I! and i2, and through those slots extend one leg each of the angular levers l3 and I4 pivotally supported by pins l5 and i8 and carrying the weights I! and it. The angular levers are supported upon the slanting arms of the cylindrical hub l9 secured to the axis 8 by the transverse pin 20. Within the hollow portion ID of the axis 8 is a rod head 2|, and against the head and around the rod 22 terminated by the head is a spiral spring 2|. The force of the spring presses the head in one direction, as illustrated towards the wheel 9. The spring also bears against the closure or screw plug 23 in the end of the hollow portion i0, and the rod passes movable through this closure. A block 24 is secured by the pin 24 to the end of rod 22 and the lock has an encircling groove 25 intended to engage, as best presented in Fig. 3, a lug 26 projecting inwardly from a U-irame 21 that is pivotally supported by the round rod 28 carried by the casing portion 5. The U-fram-e is inverted as represented in Fig. 3 and has one longer leg provided with a spring clip 29 engaging the barrel of a mercury electric switch 30. From this switch conductors 3! and 32 lead out of the end of easing portion 5 and as best shown in Fig. i connect with an alarm bell 33, or the bell may be replaced by a light, or both bell and light employed, such modifications or additions being well within the every day knowledge of average mechanics. From the bell 33 conductors 3-8 and 3? lead to a source of electrical current not shown.

The wheel 9, termed for the purposes of this explanation, a belt contact wheel, is carried by a swinging arm 35, terminating at its lower end in the clamp 34 which encircles the part 6 of the casing of the switch actuating devices, and the casing complete thus swings with the wheel towards or from the belt 2. As best shown in Fig. 1 there is provided and attached to the vertical wall of the housing I, a spring strip or piece 38 the function of which is to yieldingly limit the movement of the wheel by its own weight towards the belt. The holding strip 38 is constructed to keep the wheel in the best position for it to be adequately revolved by its contact with the belt 2.

This invention may also be advantageously used in connection with the motors that drive the belts or for other purposes.

In. the operation or this invention, considering Fig. 2, the parts being as shown at rest, the barrel of the mercury switch is inclined with its left hand end slightly lowered. In that position the mercury in the barrel would make the circuit and the alarm would ring and keep ringing providing the electric current was applied to the motor, giving notice that the belt had slowed up or was not moving. But, if the contact wheel 9 is driven by the travelling belt at suflicient speed to centrifugally throw the weights I! and [8 into the attitudes indicated by the broken lines,

the barrel of the mercury switch is tilted as indicated by the broken lines, the mercury runs down into the end of the barrel or tube, the circuit is broken, the signals cease, thus advising that the belt is moving properly, and the bell will not again sound until the belt meets further obstruction and slows down. When the motor circuits are used, the sounding 0f the bell gives notice to the attendant to quickly throw-the motor switch and out out the motor to avoid possible short circuit and consequent damage to the motors.

Having now described this invention and the manner of its use, I claim:

15 V In a conveyor alarm mechanism, the con- 7 bination with a support, of a belt arranged to 7 move vertically on one side of the support; an arm ment of the belt, and a centrifugal switch located within the casing and adapted to be operated and controlled by the revolution of said wheel and axis, 7

LLOYD P. DENDEL. 

